THE startling title of Mr. Graham Bell's admirable memoir is fully justified by its contents. It appears that there are upwards of 33,000 deaf mutes in America, mostly collected in large institutions forming social worlds of their own, whose inmates intermarry or else contract marriages with the hearing relatives of their fellow pupils, who themselves, in many cases, must have an hereditary though latent tendency to deafness. This state of things has been going on increasingly for two or more generations, with the result that congenital deafness, which in other countries appears sporadically, and mostly fails to obtain an hereditary footing, has become artificially preserved in America, and is intensified by inter-marriages, until a deaf variety of the human race may be said to be established. There can be no question, after reading the mass of evidence submitted by Mr. Graham Bell, of the general truth of this summary statement. That precise knowledge that we should be glad to possess, of the strength and peculiarity of the hereditary taint, is unfortunately unattainable owing to the imperfection of the records kept at the institutions of the after history of their pupils; but the data, such as they are, have been handled with great statistical skill by the author, so that he has squeezed all the information out of them that they appear competent to give.